Initial commit moving openolt adapter from voltha-go to the new repo.
This version works with ponsim rather than openolt, this is temporary.
It is currently being fixed to work with openolt.

Change-Id: I34a800c98f050140b367e2d474b7aa8b79f34b9a
Signed-off-by: William Kurkian <wkurkian@cisco.com>
diff --git a/python/common/utils/id_generation.py b/python/common/utils/id_generation.py
new file mode 100644
index 0000000..e0fea1c
--- /dev/null
+++ b/python/common/utils/id_generation.py
@@ -0,0 +1,116 @@
+#
+# Copyright 2017 the original author or authors.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#      http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+#
+# """ ID generation utils """
+
+from uuid import uuid4
+
+
+BROADCAST_CORE_ID=hex(0xFFFF)[2:]
+
+def get_next_core_id(current_id_in_hex_str):
+    """
+    :param current_id_in_hex_str: a hex string of the maximum core id 
+    assigned without the leading 0x characters
+    :return: current_id_in_hex_str + 1 in hex string 
+    """
+    if not current_id_in_hex_str or current_id_in_hex_str == '':
+        return '0001'
+    else:
+        return format(int(current_id_in_hex_str, 16) + 1, '04x')
+
+
+def create_cluster_logical_device_ids(core_id, switch_id):
+    """
+    Creates a logical device id and an OpenFlow datapath id that is unique 
+    across the Voltha cluster.
+    The returned logical device id  represents a 64 bits integer where the
+    lower 48 bits is the switch id and the upper 16 bits is the core id.   For
+    the datapath id the core id is set to '0000' as it is not used for voltha
+    core routing
+    :param core_id: string
+    :param switch_id:int
+    :return: cluster logical device id and OpenFlow datapath id
+    """
+    switch_id = format(switch_id, '012x')
+    core_in_hex=format(int(core_id, 16), '04x')
+    ld_id = '{}{}'.format(core_in_hex[-4:], switch_id[-12:])
+    dpid_id = '{}{}'.format('0000', switch_id[-12:])
+    return ld_id, int(dpid_id, 16)
+
+def is_broadcast_core_id(id):
+    assert id and len(id) == 16
+    return id[:4] == BROADCAST_CORE_ID
+
+def create_empty_broadcast_id():
+    """
+    Returns an empty broadcast id (ffff000000000000). The id is used to
+    dispatch xPON objects across all the Voltha instances.
+    :return: An empty broadcast id
+    """
+    return '{}{}'.format(BROADCAST_CORE_ID, '0'*12)
+
+def create_cluster_id():
+    """
+    Returns an id that is common across all voltha instances.  The id  
+    is a str of 64 bits.  The lower 48 bits refers to an id specific to that 
+    object while the upper 16 bits refers a broadcast core_id
+    :return: An common id across all Voltha instances
+    """
+    return '{}{}'.format(BROADCAST_CORE_ID, uuid4().hex[:12])
+
+def create_cluster_device_id(core_id):
+    """
+    Creates a device id that is unique across the Voltha cluster.
+    The device id is a str of 64 bits.  The lower 48 bits refers to the 
+    device id while the upper 16 bits refers to the core id.
+    :param core_id: string
+    :return: cluster device id
+    """
+    return '{}{}'.format(format(int(core_id), '04x'), uuid4().hex[:12])
+
+
+def get_core_id_from_device_id(device_id):
+    # Device id is a string and the first 4 characters represent the core_id
+    assert device_id and len(device_id) == 16
+    # Get the leading 4 hexs and remove leading 0's
+    return device_id[:4]
+
+
+def get_core_id_from_logical_device_id(logical_device_id):
+    """ 
+    Logical Device id is a string and the first 4 characters represent the 
+    core_id
+    :param logical_device_id: 
+    :return: core_id string
+    """
+    assert logical_device_id and len(logical_device_id) == 16
+    # Get the leading 4 hexs and remove leading 0's
+    return logical_device_id[:4]
+
+
+def get_core_id_from_datapath_id(datapath_id):
+    """
+    datapath id is a uint64 where:
+        - low 48 bits -> switch_id
+        - high 16 bits -> core id
+    :param datapath_id: 
+    :return: core_id string
+    """
+    assert datapath_id
+    # Get the hex string and remove the '0x' prefix
+    id_in_hex_str = hex(datapath_id)[2:]
+    assert len(id_in_hex_str) > 12
+    return id_in_hex_str[:-12]